1. Field of the Invention
The present invention relates to an electronic timepiece for displaying time by carrying out a time counting operation based on an output signal of an oscillation circuit.
2. Description of the Prior Art
In a background art, there is utilized an electronic timepiece for displaying time by carrying out a time counting operation based on an output signal of an oscillation circuit.
According to the electronic timepiece of the background art, in normal operation, the oscillation circuit is operated by a predetermined constant voltage supplied from a constant voltage circuit for carrying out a sampling operation in order to achieve low power consumption formation. Further, as a countermeasure against a case in which a terminal of a crystal oscillator constituting the oscillation circuit is leaked by stain or the like of a substrate pattern, a direct current cutting capacitor for protecting from leakage is inserted into an oscillation circuit loop to stabilize an oscillation characteristic.
However, an oscillation start characteristic of the oscillation circuit is deteriorated by the low power consumption formation, and further, a noise constituting a trigger of oscillation is difficult to be inputted by the capacitor and, therefore, a problem arises that the oscillation tart characteristic is further deteriorated.
In order to promote the oscillation start characteristic, there are proposed inventions for promoting the oscillation start characteristic of the oscillation circuit by separately providing an inverter for oscillation having a high drive function (refer to JP-A-10-206568) and providing an auxiliary amplifier portion having a high amplification factor (refer to JP-A-2002-280834).
However, since the inverter for oscillation having the high drive function or the auxiliary amplifier portion having the high amplification factor is separately provided, there poses a problem that power consumption is increased, or the constitution becomes complicated.
It is an object of the invention to be able to promote an oscillation start characteristic while having a simple constitution and maintaining low power consumption.